According to a declassified 2005 report released last week, China had been testing the effects of an electromagnetic pulse attack–the detonation of a nuclear device at high altitude to maximize the area affected by the EMP–possibly meant for Taiwan. According to the report, China was actually testing two kinds of nuclear blasts and the effects the resulting radiation would have on humans. (China was testing them on animals, which experienced “high mortality rates.”)
The point of an EMP attack (all nuclear explosions result in an EMP), however, is to disrupt the electronics devices within range of the blast. The range of the electronics damage would depend on the altitude of the blast.
“For use against Taiwan, China could detonate at a much lower altitude (30 to 40 km, according to some recent speculations) to confine the EMP effects to Taiwan and its immediate vicinity and minimize damage to electronics on the mainland,” the report from the National Ground Intelligence Center states. “The result would be a more intense EMP in a localized area. [Redacted]… A critical issue then would be the danger threshold for human exposure since human casualties (either Taiwan or U.S. military) would greatly increase the likelihood of a U.S. nuclear response.”
In other words, China was testing a way to knock out any resistance Taiwan or the U.S. could put up against its own attack on Taiwan, and was aiming for an attack that would not provoke an American nuclear assault on China in return. They were not, the report points out, looking to kill any Americans. That’s not necessarily true of Taiwanese, as the report notes: “The minimization of casualties on Taiwan is calculated to lessen the animosity among Taiwan’s populace over forced reunification.”
The report also describes a Chinese “bluff scenario” in which “China might announce a resumption of atmospheric nuclear testing and warn of tests during a specified time period, then strike Taiwan with the conventional infrastructure attack during the specified period. They would then wait to see whether the United States would call their bluff by moving the [Aircraft Carrier Battle Groups) to defend Taiwan. This bluff scenario would be accompanied by prior announcements/leaks of their intentions (which seems to be the case as sources for this article confirm).”